Failure rates of stemmed metal-on-metal hip replacements

Concerns about metal-on-metal large-head hip replacements are accurately addressed by Alison Smith and colleagues1 in their analysis of data from the National Joint Registry of England and Wales. The expected advantages of metal-on-metal prostheses, allowing for larger head sizes, have been replaced by great concern because of local soft-tissue reactions to debris from accelerated metal wear and elevated concentrations of metal ions in the bloodstream.2

The Dutch Orthopaedic Association (NOV) issued advice to all its members after extensive discussion during a special metal-on-metal session at the 2011 NOV Spring meeting. This advice included active follow-up of all patients with metal-on-metal hip implants, provision of detailed information to patients, and measurement of metal ion concentrations in the blood.

On the basis of the rising number of publications reporting an increased complication rate with metal-on-metal large-head hip replacements,1, 3 this advice was recently revised and a suspension of the use of these implants was issued (panel). This advice was unanimously adopted by members present at our annual NOV meeting in January, 2012. To the best of our knowledge, the NOV is the first national orthopaedic association to advise against the use of all metal-on-metal large-head hip implants.

Advice of the Dutch Orthopaedic Association

Suspend use of all metal-on-metal replacements with large heads (≥36 mm), including resurfacing replacements, until the safety and long-term effectiveness have been established conclusively

Wait for long-term national and international results to arrive in order to provide prospective patients with advice

Further use will only be possible within the framework of scientific research that satisfies the criteria of good clinical practice

Summon all patients who have had metal-on-metal replacements in the past to an annual check-up, for the next 5 years at least, to include assessment of cobalt ion concentrations in blood and x-ray diagnostics

Inform such patients about the risks that have so far been established

In case of complaint, widen examination to the use of metal artifact reduction sequence (MARS) MRI, CT, or ultrasound imaging

Indicate on hospital websites whether metal-on-metal replacements have been used in the past

Future developments will decide whether our advice is temporary, because of uncertainties, or a prelude to the termination of these types of hip prosthesis. Safety should prevail in such moments.

CCPMV is a board member of the Dutch Orthopaedic Association. JANV is President of the Dutch Orthopaedic Association.